The first case was traced
To a patient in the latter half
Of the last century
Through a trail of bodies
It's a new strain of an old plague
The vector in question in quarantine
Gave us its name and pathologies
Quoting:

I breathe disease
And people start dropping off
All around me
Don't come near me

The host's diagnosis
Uncovered encoded instructions
For self-destructing
In his diary
The surgeons resected it
Sentence by sentence
Each isolated regenerated
The full text in seconds
The last entries all reading:

I talk and
The germ theory of thought
Grows ever more convincing to me
And the cure-
If it's my bad ideas
They're catching-
Kill me
Mercy